1. Field of the Invention
The present invention provides medicinally active extracts and fractions, and methods of preparing the same, from components of Ganoderma lucidum. These extracts and fractions have been found to be especially active in inhibiting tumor growth, modulating immune response, and increasing hematopoietic activity.
2. Description of the Related Art
Ganoderma lucidum (Reishi or Ling-Zhi) has been used in traditional Chinese medicine (TCM) as anti-tumor and immnuo-modulating agent. It also exhibits liver protective, hypoglycemic and platelet aggregation-inhibiting activities1a, in addition to being effective in treating hypertension and neoplasia1b. The active constituents responsible for each of these activities have been qualitatively described, but the molecular basis of their action has not been elucidated. Of particular significance among these functions is its immnuo-modulating and anti-tumor activities.2,3 Previous studies have shown that the polysaccharide components of Reishi exhibit the anti-tumor activity2 and are able to stimulate the expression of CD4 and T-cell counts during or after chemotherapy. The saccharides contain either a polysaccharide backbone with β-1,3-linkages3,4 or a polymannose backbone with β-1,4-linkages,5a both with side chains of unknown structure (Scheme 1). The real carbohydrate epitope responsible for the anti-tumor activity and its receptor has not been identified, though the receptor CR3 has been shown to bind the β-glucan polysaccharide with undefined side chains.3b 